Sensing Optical Fibers for Earthquake Source Characterization Using Raw DAS Records - Archive ouverte HAL Access content directly
Journal Articles Journal of Geophysical Research : Solid Earth Year : 2024

Sensing Optical Fibers for Earthquake Source Characterization Using Raw DAS Records

Claudio Strumia
Alister Trabattoni
Mariano Supino
Marie Baillet
Diane Rivet
Gaetano Festa

Abstract

Abstract Distributed Acoustic Sensing (DAS) is becoming a powerful tool for earthquake monitoring, providing continuous strain‐rate records of seismic events along fiber optic cables. However, the use of standard seismological techniques for earthquake source characterization requires the conversion of data in ground motion quantities. In this study we provide a new formulation for far‐field strain radiation emitted by a seismic rupture, which allows to directly analyze DAS data in their native physical quantity. This formulation naturally accounts for the complex directional sensitivity of the fiber to body waves and to the shallow layering beneath the cable. In this domain, we show that the spectral amplitude of the strain integral is related to the Fourier transform of the source time function, and its modeling allows to determine the source parameters. We demonstrate the validity of the technique on two case‐studies, where source parameters are consistent with estimates from standard seismic instruments in magnitude range 2.0–4.3. When analyzing events from a 1‐month DAS survey in Chile, moment‐corner frequency distribution shows scale invariant stress drop estimates, with an average of Δ σ = (0.8 ± 0.6) MPa. Analysis of DAS data acquired in the Southern Apennines shows a dominance of the local attenuation that masks the effective corner frequency of the events. After estimating the local attenuation coefficient, we were able to retrieve the corner frequencies for the largest magnitude events in the catalog. Overall, this approach shows the capability of DAS technology to depict the characteristic scales of seismic sources and the released moment.
Fichier principal
Vignette du fichier
JGR Solid Earth - 2024 - Strumia - Sensing Optical Fibers for Earthquake Source Characterization Using Raw DAS Records.pdf (3.86 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Licence : CC BY - Attribution

Dates and versions

hal-04463324 , version 1 (17-02-2024)

Identifiers

Cite

Claudio Strumia, Alister Trabattoni, Mariano Supino, Marie Baillet, Diane Rivet, et al.. Sensing Optical Fibers for Earthquake Source Characterization Using Raw DAS Records. Journal of Geophysical Research : Solid Earth, 2024, 129 (1), ⟨10.1029/2023JB027860⟩. ⟨hal-04463324⟩
48 View
4 Download

Altmetric

Share

Gmail Facebook X LinkedIn More